MXene@Ag-based ratiometric electrochemical sensing strategy for effective detection of carbendazim in vegetable samples.

In this paper, a novel ratiometric electrochemical sensor for carbendazim (CBZ) detection was constructed by a composite of MXene@Ag nanoclusters and amino-functionalized multi-walled carbon nanotubes (MXene@AgNCs/NH-MWCNTs). The Ag nanoclusters (AgNCs) embedded in the MXene not only could inhibit the aggregation of MXene flakes and enhance the electrocatalytic ability, but also serve as an internal reference probe for the ratiometric electrochemical detection. Moreover, the introduction of NH-MWCNTs can further improve the electrochemical signals of CBZ and Ag, resulting in the enhanced signal amplification and higher sensitivity. Based on these characteristics of the MXene@AgNCs/NH-MWCNTs composite, the proposed sensor exhibits a favorable linear relationship between I/I and the concentration of CBZ ranging from 0.3 nM to 10 μM and a low limit of detection of 0.1 nM. Moreover, the proposed ratiometric electrochemical sensing platform also demonstrates high selectivity, good reproducibility, secular stability, and satisfactory applicability in vegetable samples.